Fix non-deterministic delays when accessing a vcpu that was in "running" or

"sleeping" state. This is done by forcing the vcpu to transition to "idle"
by returning to userspace with an exit code of VM_EXITCODE_REQIDLE.

MFC after:      2 weeks

1 files changed, 13 insertions, 1 deletions

diff --git a/usr.sbin/bhyve/bhyverun.c b/usr.sbin/bhyve/bhyverun.c
index 47a7699..ee0f106 100644
--- a/usr.sbin/bhyve/bhyverun.c
+++ b/usr.sbin/bhyve/bhyverun.c
@@ -100,7 +100,7 @@ static struct vm_exit vmexit[VM_MAXCPU];
 
 struct bhyvestats {
         uint64_t        vmexit_bogus;
-        uint64_t        vmexit_bogus_switch;
+	uint64_t	vmexit_reqidle;
         uint64_t        vmexit_hlt;
         uint64_t        vmexit_pause;
         uint64_t        vmexit_mtrap;
@@ -461,6 +461,17 @@ vmexit_bogus(struct vmctx *ctx, struct vm_exit *vmexit, int *pvcpu)
 }
 
 static int
+vmexit_reqidle(struct vmctx *ctx, struct vm_exit *vmexit, int *pvcpu)
+{
+
+	assert(vmexit->inst_length == 0);
+
+	stats.vmexit_reqidle++;
+
+	return (VMEXIT_CONTINUE);
+}
+
+static int
 vmexit_hlt(struct vmctx *ctx, struct vm_exit *vmexit, int *pvcpu)
 {
 
@@ -571,6 +582,7 @@ static vmexit_handler_t handler[VM_EXITCODE_MAX] = {
 	[VM_EXITCODE_VMX]    = vmexit_vmx,
 	[VM_EXITCODE_SVM]    = vmexit_svm,
 	[VM_EXITCODE_BOGUS]  = vmexit_bogus,
+	[VM_EXITCODE_REQIDLE] = vmexit_reqidle,
 	[VM_EXITCODE_RDMSR]  = vmexit_rdmsr,
 	[VM_EXITCODE_WRMSR]  = vmexit_wrmsr,
 	[VM_EXITCODE_MTRAP]  = vmexit_mtrap,